A large number of Zevi’s followers also converted to Islam and they were called Dönmehs (meaning ‘converted’ in Turkish). They attended services at the mosque, but like their ‘messiah’, they practiced Jewish rituals in secret. Thessaloniki was home to the largest community of Dönmehs in the Ottoman Empire, at 15,000 at the turn of the 20th century. They mostly resided Ano Poli (Upper Town) and had their own educational and religious institutions, judges and leaders. They played a crucial role in the Young Turks revolution, and also contributed greatly to the development of western culture in the city. Yeni Camii (aka the new mosque) was built in 1902 by the architect Vitaliano Poselli for the Dönmehs, and from 1923 to 1963 housed the Archaeological Museum of Thessaloniki.